Abstract:
In order to investigate the optimal process parameters of microwave vacuum drying of Angelica sinensis, “Mingui No.1” from Dingxi, Gansu Province was used as the test material. High performance liquid chromatography(HPLC) was used to determine the contents of ligustilide(LA), ferulic acid(FA), senkyunolide H(SH), senkyunolide I(SI), chlorogenic acid(CA), 3-butylidene phthalide(BA), antioxidant properties(DPPH), total phenols(TPC), total flavonoids(TFC), polysaccharides(Pc), and dried product rehydration ratio were measured in Angelica sinensis under different drying temperatures, slice thickness and vacuum conditions, and the composite weights and comprehensive scores of each active ingredient in angelica were calculated by AHP-entropy weighting method; the optimal process parameters for microwave vacuum drying of Angelica sinensis were determined by the Box-Behnken response surface method with the integrated score as the response value. The results showed that the Q
j values of LA、FA、SH、SI、CA、BA、DPPH、TPC、TFC、Pc、RR in samples were calculated by AHP-entropy weighting method as 0.159、0.192、0.120、0.288、0.033、0.063、0.059、0.041、0.024、0.013、0.009, respectively. The optimal process conditions for microwave vacuum drying of Angelica sinensis were obtained by Box-Behnken response surface method, with drying temperature of 50 ℃, slice thickness of 5 mm, and vacuum degree of-0.070 MPa, and with an overall score of 84.95. In addition, the microscopic electron microscopy results also showed that under these process conditions, the sample had a uniform and regular honeycomb pore structure with the best qualitative thermal stability. Therefore, the AHP-entropy weight method, which calculates the composite weights, can be used for the optimization of multiple objectives in the microwave vacuum drying process of Angelica sinensis.